CAMRT Radiography Practice Exam

What effect does a smaller field of view (FOV) have on the image brightness?

1. Increases brightness

2. Decreases brightness

3. No effect on brightness

4. Only enhances brightness in certain conditions

The correct answer is: Decreases brightness

A smaller field of view (FOV) generally results in decreased image brightness due to the increased concentration of radiation on a smaller area, which may lead to higher contrast in the image. When the FOV is reduced, the system may receive less scattered radiation, which can cause an overall dimming effect in the image. Additionally, a smaller FOV can lead to higher pixel density in digital systems, which might require adjustments in the processing algorithms to compensate for brightness levels. In radiography, the amount of data collected and the associated exposure factors play crucial roles in the final image quality. Thus, with a smaller FOV, there can be an effect on the image’s exposure, leading to less light or brightness being represented because the area being viewed is more restricted compared to a larger FOV. Bridging into digital imaging, post-processing techniques may enhance overall brightness, but inherently, a smaller FOV tends to reduce the base brightness captured in the initial exposure.